Sealants, adhesives and other flowable materials are commonly used in a variety of manufacturing and other applications, including, for example aircraft, appliance and automobile manufacturing. In some applications, the flowable materials are provided in a pre-proportioned cartridge. The cartridge is then inserted into a caulking gun, which is used by a technician to manually apply the flowable material to an article of manufacture. This approach is time and labor intensive. An improved dispenser mechanism for automatically dispensing flowable material from a pre-proportioned cartridge is desirable.